1. Field of the Invention
The present invention relates to an image processor which may be used in cases where an image is received by selecting a desired scanner from among a plurality of scanners.
2. Discussion of the Related Art
With progress in office automation, a system has been developed in which cables are laid in offices, and document processors such as work stations and various input/output devices are connected to the cables so as to make effective use of various items of information.
FIG. 4 illustrates essential portions of such a system. Image processors 12-1, 12-2, . . . , typified by work stations, scanners 13-1, 13-2, . . . , for inputting images, printers 14-1,14-2, . . . , for printing out images, and so on are connected to a cable 11 constituting a local area network. For instance, the operator of the first image processor 12-1 is capable of inputting an image by selecting a desired scanner from among the scanners 13-1, 13-2, . . . , by taking into account various conditions such as the fact that the document to be read is a color document, or is large in size. The same holds true of the selection of a printer from among the printers 14-1, 14-2, . . . . In such a system, it is possible to add additional devices to the cable 11, including new scanners and printers, as well as a mail server 15 and a communication server 16, as required.
The different types of scanners employ a number of different methods of transferring image information. For instance, the first scanner 13-1 has a large-capacity buffer memory, and is arranged such that after one page of image information is read, the image information is transferred to the image processor 12. In cases where the image processor 12 receives the image information transferred from the scanner 13-1, there is no need to take the reading speed of the scanner 13-1 into consideration.
Meanwhile, if it is assumed that the second scanner 13-2 is a synchronous-type scanner with a relatively small-capacity buffer memory, the transfer of image information is carried out in predetermined unit amounts in synchronism with the image processor 12. At this time, the mode of transfer of image information will also vary depending on the amount of data that can be handled by the image processor 12 and the scanner 13-2.
In the above, a description has been given of the types of scanners in connection with a buffer and the presence or absence of synchronization with the image processor. The scanners can be classified into more kinds depending on the types of data, such as the image information being color information, binary data, or data in a form other than base 2. It has been the practice, among others, to finely adjust a method of transferring signals to enable communication with the scanner 13 or to install an interface circuit on the image processor 12 at the time the image processor 12 has selected a desired scanner 13.
With such conventional techniques, however, each time a scanner 13 is selected, it is necessary to perform operations such as exchanging the interface circuit or adjusting each circuit terminal in order to make the image processor correspond to the scanner. Also, in cases where signal processing is controlled by software, it has been necessary to alter the program. Such operations are time-consuming and expensive. Hence, even though the various types of scanners 13-1, 13-2, . . . , are connected to the cable, it has been impossible to make efficient use of them.
It is possible to eliminate the burden on the image processor side by making common use of the scanners themselves. However, in the such attempts for common use have required that the functions peculiar to the individual scanners be ignored.